How a Spinal EKG Grades a Soft Tissue Injury

Published on October 1, 2026

A test that says abnormal is only half useful

Man with knee injury A Spinal EKG does not stop at telling you that your muscles are guarding. It grades how strongly they are guarding, motion by motion, into four categories: normal, mild, moderate, and severe. This article explains what is being graded, what each grade looks like on the graph, what it changes about care, and, just as important, what a grade is not. If the test itself is new to you, start with the patient’s guide to DynaROM testing and come back.

One thing to hold onto throughout. A grade describes how your spinal muscles behaved during the motions tested on the day of the test. It is not a pain score, it is not an impairment rating, and it is not, on its own, proof of injury. It is a structured way of describing an involuntary muscular response so that it can be compared over time and a clinical treatment recommendation can be formulated.

What is actually being graded

The grade is assigned to each motion by the interpreting clinician, choosing from a defined set of descriptors in the reporting software. It is a clinical characterization of the recording, not a single number crossing a threshold. Six measured domains feed into it.

Range of motion. How far you moved on that motion, in degrees, compared with the reference values published in the AMA Guides. The report shows both the degrees and the percentage of the reference value.
Flexion relaxation. Whether the muscles relax where they should. On forward bending in particular, healthy lower back muscles go quiet at full flexion. Muscles that keep firing there are guarding.
Movement quality. A smooth, rounded range of motion curve is normal. A jagged one, with small stops and restarts, or a shallow slope that shows slow, hesitant movement into the end of the range, is what moving through pain looks like.
Muscle guarding. How much electrical activity the muscles produce during the motion, measured in microvolts, and whether it is hyperactive or erratic rather than smooth.
Bilateral symmetry. The left and right sides of the spine should behave in a predictable relationship to each other. On side bending, for example, the muscles opposite the direction of the bend normally work harder, so their trace sits on top, and the left bend is compared with the right bend against that expected pattern. When both sides recruit at about the same amplitude regardless of direction, that is bracing, an involuntary guarding response.
Trial consistency. Each motion is recorded two or three times. Results that repeat across trials are more meaningful than a single unusual trace.

The four grades

Normal

The muscles do what healthy muscles do. Activity rises with the motion and falls when the motion is complete, the flexion-relaxation response is present where expected, and the range of motion curve is smooth. In the report’s own language, a normal motion is one where the left and right sides recruit independently, with little opposite-side bracing or guarding.

One detail matters here. Normal describes the guarding pattern on that motion. It does not override a separately reported limitation in range. A motion can be graded normal for guarding and still show reduced range of motion, and the report presents both.

Mild

Guarding is present but limited. In the report’s language, mild muscle guarding with a mildly abnormal motion pattern and reduced endpoint range of motion. Typically this looks like modestly elevated activity that still mostly resolves, a slight asymmetry between sides, or a small hitch in an otherwise normal motion curve. A mild grade is read alongside the motion x-ray (DRMA) findings rather than on its own: mild guarding with a significant ligament finding is a different picture from mild guarding with normal imaging.

Moderate

Guarding is clearly present and affects the motion. In the report’s language, moderate guarding with marked hyperactive or variable recruitment, correlating with discomfort in this motion. The muscles fail to relax where they should, or one side works substantially harder than the other, or the motion curve shows the ratcheting pattern of movement through pain. A moderate grade generally means the injured region is being actively protected by the nervous system on that motion.

Severe

Guarding dominates the motion. In the report’s language, a pronounced guarding pattern with substantial left and right recruitment imbalance and limited motion. Activity is markedly elevated, relaxation is absent, asymmetry is pronounced, or the motion itself is substantially restricted by the muscular response. A severe grade on a motion is a signal to look carefully at what is being protected, and, where there are also neurological signs, a reason for a specialized chiropractic and medical evaluation, including neurological testing and imaging, before hands-on care proceeds.

One grade per motion, not one grade per person

This is the part of the report most often misread.

The standard protocol tests six motions, and each receives its own grade. A person can be normal on rotation and severe on forward bending, and that is not a contradiction. It is information about which motions load the injured tissue.

The report also carries a summary, and the summary reflects the most severe grade found among the motions tested. If one motion out of six was graded severe, the overall outcome will read severe, followed by the report’s standard wording that abnormal muscle guarding was identified in one or more motions, and it will name the motions where the findings were most pronounced. Reading the summary word alone, without the motion-by-motion detail beneath it, gives a distorted picture in both directions: it can make a single problem motion sound like a global one, and it can hide the fact that five motions were normal. The detail is where the clinical meaning lives.

What a grade changes

In practical terms, the grade influences three things: how intensive the initial care plan is, how soon the test is repeated, and whether anything needs to happen before hands-on treatment begins. Severity is the single biggest influence on visit frequency. A severe grade means it is a higher probability for outside imaging (such as an MRI), but a test program of conservative treatment is often utilized to evaluate improving symptoms.

Grades over time are the point

A single grade is a snapshot. The reason to grade at all is to compare.

Repeating the Spinal EKG at intervals across a course of care produces a sequence: moderate on forward bending at the first visit, mild six weeks later, normal at three months, for instance. That sequence documents that the involuntary protective response is resolving, which is a different kind of evidence from a patient reporting that they feel better, and it is useful precisely because it does not depend on the patient’s own account.

It also works in the other direction. A grade that stays fixed across several re-tests, while care continues, is one of the signals a clinician weighs in judging whether a patient has reached maximum medical improvement, the point at which the condition has stabilized and further treatment is unlikely to change it. The test does not make that determination on its own, and it does not predict future pain. It shows whether the muscles are still protecting something.

What a grade is not

It is not, by itself, an impairment rating. Impairment under the AMA Guides to the Evaluation of Permanent Impairment is assigned by an examiner applying the Guides’ criteria. Muscle guarding is one of those criteria: the Fifth Edition’s Diagnosis-Related Estimate method lists muscle guarding or spasm observed on examination among the findings that place a spinal injury in a ratable category. A Spinal EKG that documents severe guarding persisting a year or more after a crash is objective evidence of that finding. The rating itself is still the examiner’s to make.
It is not proof of injury. Guarding is a response to something, and the grade describes the strength of the response. Identifying what is being protected takes the rest of the evaluation. The manufacturer’s own report template says this in its limitations section: no single test independently establishes injury or disability, and the examination should not be used alone to determine the existence, location, severity, permanence, or cause of an injury.
It is not a pain score. People with mild guarding can be in significant pain, and the reverse happens too. The grade describes what the muscles are doing, not what the person is feeling.
It is not universally accepted. Several major insurers classify dynamic surface EMG as investigational for diagnostic use, and the grades are clinician-assigned descriptors from the manufacturer’s reporting software, not a national standard. Insurers have also litigated the underlying question and lost: in Florida, a rule classifying surface EMG as not medically necessary was struck down in 2005 and affirmed on appeal in 2006, over the intervention of the insurance industry’s national trade associations. The grade is most defensible when it is presented as what it is: a structured description of muscle behavior, repeated over time.

Frequently asked questions

What does a severe result on a Spinal EKG mean?

It means that on at least one of the motions tested, the muscles along the spine showed a pronounced protective response: in the report”s own words, a pronounced guarding pattern with substantial left and right recruitment imbalance and limited motion. It describes the strength of the guarding on that motion. It is not by itself a diagnosis, and if neurological signs are also present it is a reason for further specialized neurological testing, which Dr. Schmidt performs at the clinic, and for imaging before hands-on care.

Can a Spinal EKG be normal if I still have pain?

Yes. Guarding is one way the body responds to injury, and not every painful condition provokes it on the motions tested. A normal grade means no meaningful guarding was recorded during those specific movements on that day. It does not mean your pain is not real, and it does not mean nothing is wrong. Other parts of the evaluation, including motion imaging, look at things this test cannot see.

Does a mild grade mean my injury is minor?

Not necessarily. The grade describes how strongly the muscles are protecting a region, not how badly the underlying tissue is injured. A mild grade is common as an injury resolves, and it is also seen in some people with significant ligament findings on motion x-ray (DRMA) imaging. The grade and the imaging answer different questions.

How often is the test repeated?

It depends on the initial findings and the care plan. In general the test is repeated at intervals during care so that the grades can be compared over time, because the trajectory is more informative than any single result.

Is the Spinal EKG grade the same as an impairment rating?

Not by itself. Impairment ratings under the AMA Guides are assigned by an examiner applying the Guides” criteria. Muscle guarding or spasm observed on examination is one of the findings the Fifth Edition”s DRE method uses to place a spinal injury in a ratable category, so a Spinal EKG documenting persistent guarding can be part of the evidence an examiner relies on. The grade itself is not the rating.

Why does my report say severe when most of my motions were normal?

Because the overall outcome reflects the most severe grade found among the motions tested. One severe motion out of six produces an overall outcome of severe, with wording that abnormal muscle guarding was identified in one or more motions and naming where it was most pronounced. The motion-by-motion detail beneath the summary is the part that describes your actual pattern.

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How a Spinal EKG Grades a Soft Tissue Injury